I was having some problems with Heroes VI crashing all the time and after some research on these forums, learnt that it may be a problem with the game causing my graphics card to overheat, so I lowered the resolution and the graphical settings from high to low. (I have a Radeon HD 7850 that plays games like Crysis 2 on ultra settings, so the card SHOULD be able to handle Heroes VI).
Unfortunately, since then I cannot open the game. When I try and launch the game from the disc or via Uplay, I can hear the opening music and the introduction speech ("It all went wrong the day our Father, the Duke of Griffin, died.") but the actual game itself won't load and my PC freezes at the Windows 7 desktop.
I've tried uninstalling and reinstalling the game, but the problem persists. I only purchased the game about a month ago, so I'm pretty annoyed I can't seem to play it.